The present invention relates to an active-matrix liquid crystal display device, a repair method thereof and drive method thereof, and in particular relates to an active-matrix liquid crystal display device of the transverse electric field type, a repair method thereof, and a drive method thereof.
Recently, together with advancements in personal computers, the trend has been for an increase in the demand for liquid crystal display devices, particularly for active-matrix liquid crystal display devices. Moreover, this trend is not limited to personal computers, and the demand for liquid crystal television (hereafter abbreviated as liquid crystal TV) is also on the rise.
One of the properties demanded of liquid crystal TVs is a broad viewing angle. A variety of different types of liquid crystal display devices have been developed in order to achieve a broad viewing angle. Among those, particular interest has been given to active-matrix liquid crystal display devices of the transverse electric field type (IPS (In-Plane Switching) mode).
Generally, in active-matrix liquid crystal display devices, a liquid crystal is injected between two glass substrates, with one of the glass substrates being provided with a plurality of signal line (data line) groups and a plurality of scanning line (gate line) groups that intersect to form a matrix. Furthermore, thin film transistors (TFTs) are disposed at each portion where the signal lines and scanning lines intersect.
In the case of active-matrix liquid crystal display devices of the transverse electric field type, pixel electrodes for controlling the arrangement of the liquid crystal at each pixel, and opposing electrodes forming a pair with the pixel electrodes, are further provided on the same substrate.
When displaying an image, the scanning lines are scanned, and the thin film transistors at the intersecting portions are turned on. When a thin film transistor is turned on, the signal potential inputted in the signed line is written onto the pixel electrode. When this happens, an electric potential difference is applied between the pixel electrode and the opposing electrode, and an electric field (transverse electric field) parallel to the substrate surface is created, and thus the liquid crystal changes from an initial alignment to a new alignment. Therefore, the amount of light that passes through the liquid crystal layer can be adjusted. That is, the polarization of light passing through the liquid crystal changes according to the applied signal voltage, and depending on that polarization, a light or dark pixel is displayed on the display screen.
In active-matrix liquid crystal display devices of the transverse electric field type, the liquid crystal molecules are always in a state parallel to the substrate, so that compared to conventional liquid crystal display panels, in which the pixel electrodes and the opposing electrodes are disposed perpendicular to the panel, the contrast does not easily change even if the panel is viewed from an oblique angle, and thus viewing angle properties can be considerably improved.
Conventional active-matrix liquid crystal display devices of the transverse electric field type are described in further detail below. FIG. 21(a) is a plan view illustrating the arrangement of the electrodes, wiring, and the like in a single pixel in a liquid crystal display panel provided in a conventional active-matrix liquid crystal display device of the transverse electric field type, and FIG. 21(b) is a cross-sectional view of that liquid crystal display device. Also, FIG. 22(a) is a plan view illustrating the arrangement of the electrodes, wiring and the like in a single pixel in a liquid crystal display panel provided in another conventional active-matrix liquid crystal display device of the transverse electric field type, and FIG. 22(b) is a cross-sectional view of that liquid crystal display device.
As shown in FIGS. 21(a) and (b), the liquid crystal display panel has an array substrate 1001 and an opposing substrate 1002 both made of the glass substrates and disposed in opposition to one another, and a liquid crystal layer 1003 provided between the two. Formed on the surface of the array substrate 1001 is a plurality of scanning lines 1004 having a fixed spacing between one another, a plurality of signal lines 1005 that intersect with the scanning lines 1004, pixel electrodes 1006 provided at each pixel, opposing electrodes 1007 forming a pair with the pixel electrodes 1006, and TFTs 1008 that function as switching elements between the pixel electrodes 1006 and the signal wires 1006. Furthermore, the opposing electrodes 1007 are disposed parallel to the scanning lines 1004. Also, a transparent insulating layer 1009 is formed on the array substrate 1001 such that it covers the scanning lines 1004 and the opposing electrodes 1007. The pixel electrodes 1006 are made of a plurality of pixel electrode portions 1006a and linking portions 1006b for linking the plurality of pixel electrode portions 1006a. The linking portions 1006b are provided on the scanning lines 1004. Additionally, the opposing electrodes 1007 are made up of a plurality of opposing electrode portions 1007a and an opposing electrode wire 1007b for linking the plurality of opposing electrode portions 1007a. Furthermore, storage capacity portions 1015 are provided on the portions where the scanning lines 1004 and the linking portions 1006b overlap.
More specifically, the TFTs 1008 are provided on the array substrate 1001 and include a gate electrode 1010, a silicon layer 1011, which is selectively provided on the insulating layer 1009, a source electrode 1012, and a drain electrode 1013.
The source electrodes 1012 are connected to the signal wires 1005, and the drain electrodes 1013 are connected to the pixel electrodes 1006. The pixel electrode portions 1006a and the opposing electrode portions 1007a are arranged in alternation. Thus, an electric field substantially parallel to the array substrate 1001 is generated between the pixel electrode portions 1006a and the opposing electrode portions 1007a, and the alignment of the liquid crystal molecules is controlled at each pixel.
Also, an alignment film 1014 for aligning the liquid crystal is formed on the array substrate 1001 so that it covers the scanning lines 1004, the signal lines 1005, the pixel electrodes 1006, the opposing electrodes 1007, and the TFTs 1008.
On the other hand, the opposing substrate 1002 is made of a glass substrate, the inner surface side of which is provided with a color filter (not shown in the drawings). Furthermore, an alignment film 1014 is also formed so as to cover this color filter. The alignment films 1014 and 1014 are made of polyimide, the surface of which has been processed by rubbing. The rubbing process is performed by rubbing a surface with a roller coated with a fabric such as rayon.
Additionally, polarizers (not shown in the drawings) are provided on the outer sides of the array substrate 1001 and the opposing substrate 1002. The two polarizers are disposed such that their respective polarizing axes are in cross nicol arrangement. Note that in the scenario described above, the linking portions 1006b are provided above the scanning lines 1004 in the pixel electrodes 1006, but as shown in FIG. 22, it is also possible to provide the linking portions 1006b above the opposing electrode wiring 1007b in the opposing electrodes 1007. In that configuration, storage capacity portions 1016 are provided between the linking portions 1006b and the opposing electrode wire 1007b. 
As described earlier, in conventional IPS mode liquid crystal display devices, the insulating layer 1009, which is made of silicon nitride, is provided between the layer of pixel electrodes 1006 and the layer of the opposing electrodes 1007, so that both layers are insulated from each other by the insulating layer 1009. However, because the insulating layer 1009 is thin, portions where the pixel electrodes 1006 and the opposing electrodes 1007 three-dimensionally intersect, for example at a defective location 1017 shown in FIG. 21(a), may become conductive when foreign substances, for example, have mixed into the insulating layer 1009. Also, portions where the linking portions 1006b and the scanning lines 1004 overlap (storage capacity portions 1015), for example at a defective location 1018 shown in FIG. 21(a) and a defective location 1019 shown in FIG. 23(a), may become conductive for the same reason.
Moreover, when viewed horizontally, the pixel electrodes 1006 and the opposing electrodes 1007 are normally designed such that they are formed at a spacing of several microns to several dozen microns. Consequently, when patterning is performed with a photolithography step, electrical short-circuits occur easily between the pixel electrodes 1006 and the opposing electrodes 1007 (defective location 1020 shown in FIG. 21(a) and defective location 1021 shown in FIG. 22(a)), or between the pixel electrodes 1006 and the scanning lines 1004, when there are pattern defects between the two electrodes.
When current is conducted, or when short-circuits occur, between the pixel electrodes 1006 and the opposing electrodes 1007 in this way, the electric potential between both electrodes drops, thereby causing the problem that all of the pixels turn dark or white and become display defective pixels (hereafter abbreviated simply as xe2x80x9cbad pixelsxe2x80x9d).
The existence of these bad pixels is a problem in particular in liquid crystal TVs. In the case of displays for personal computers, the level of the resolution is that of XGA (Extended Graphics Array) or SXGA (Super Extended Graphics Array). On the other hand, liquid crystal TVs have a resolution level of NTSC (National TV Standards Committee), and have a lower resolution than displays for personal computers. Consequently, the pixel size in liquid crystal TVs is larger than that of displays for personal computers. Therefore, pixel defects in liquid crystal TVs are more easily visible than pixel defects in displays for personal computers. For this reason, bad pixels must be recovered to improve yield when manufacturing display devices.
As explained above, the occurrence of bad pixels resulting from the conduction of current or short-circuits caused by impurities between the pixel electrodes 1006 and the opposing electrodes 1007 is normally repaired by cutting off the pixel electrodes from the TFTs by the irradiation of laser light. For example, irradiating laser light on a repair location 1022 with respect to the defective location 1018 cuts away the pixel electrode 1006 and the defective location 1018, and the recovery of bad pixels is achieved. However, there was the problem that pixels did not operate after being repaired, and the entire pixel went completely black when on. There was also the problem, for example, that even if repaired pixels could be operated, if the storage capacity portion 1015 had been cut off, the conduction in the storage capacity portion 1015 caused charge leaks from the liquid crystal capacity that resulted in the dropping of the brightness of that pixel, and in display nonuniformities, for example.
Also, as is disclosed in the Japanese Unexamined Patent Publication 05-333376, a method has been proposed for providing two TFTs on a single pixel in advance, so that even if one of the TFTs and pixel electrodes is cut off and becomes inactive after laser light has been irradiated, pixel activation is ensured by the other TFT, and the pixel can be prevented from becoming defective. With this repair method, however, in a normal case wherein pixel defects do not occur, there was the problem that because an unnecessary TFT existed in each pixel, the numerical aperture of the pixels dropped and the transmissivity of the pixels was lowered.
In view of the problems of the related art, it is an object of the present invention to provide a liquid crystal display device, in which a decrease in transmissivity can be impeded and an increase of yield can be achieved by recovering bad pixels, a pixel repair method and a drive method for same.
In order to achieve this object, a liquid crystal display device in accordance with the present invention, wherein a liquid crystal layer is formed between a pair of substrates, and wherein liquid crystal in the liquid crystal layer is driven by an electric field that is parallel to the substrate surface, wherein provided on one substrate of the pair of substrates are a plurality of gate lines, a plurality of data lines provided such that the data lines intersect with the plurality of gate lines, switching elements associated with points where the plurality of gate lines and the plurality of data lines intersect, and which are connected to the gates lines and the data lines, pixel electrodes connected to the data lines via the switching elements, and opposing electrodes forming pairs with the pixel electrodes, wherein a plurality of storage capacities for maintaining a charge of the pixel electrode are provided in a distributed arrangement associated with points where the plurality of gate lines and the plurality of data lines intersect.
With this configuration, switching elements are provided for each point where the plurality of gate lines and the plurality of data lines intersect, or in other words: a switching element is provided for each pixel. Furthermore, each pixel is provided with a plurality of storage capacities in a distributed arrangement. Here, each pixel is provided with a plurality of storage capacities xe2x80x9cin a distributed arrangementxe2x80x9d means that if, for example, one of the plurality of storage capacities is electrically short-circuited and cannot operate normally, and then this defective storage capacity is cut off, then the other storage capacities are arranged such that they can still operate.
Consequently, with this configuration, even when a storage capacity with a defect is cut off, then the other storage capacities still function normally, so that regularly functioning storage capacities compensate for the storage capacity with the defect and fluctuations in the potential of the pixel electrode can be inhibited. Therefore, comparing pixels in which a defect storage capacity has been cut off with regular pixels, it is possible to suppress extreme discrepancies in brightness and flicker properties. Thus, bad pixels can be made more inconspicuous on the display screen, and an increase in yield can be achieved.
In the above configuration, it is possible to adopt a configuration, in which at least some of the plurality of storage capacities are arranged in series.
It is further possible to adopt a configuration, in which a bypass is provided for bypassing the storage capacity from among the plurality of storage capacities arranged in series that is closest to the switching element.
In this configuration, it is further possible to adopt a configuration, in which at least some of the plurality of storage capacities are arranged in parallel.
In this configuration, it is further possible to adopt a configuration, in which at least some of the plurality of storage capacities are arranged in a loop.
Here, xe2x80x9carranged in seriesxe2x80x9d, xe2x80x9carranged in parallelxe2x80x9d, and xe2x80x9carranged in a loopxe2x80x9d does not mean that the electrical connections in the equivalent circuit are in parallel or in series for example, but rather the concept of how the plurality of storage capacities are arranged in one pixel. FIG. 20 is a diagram illustrating schematically how a plurality of storage capacities can be arranged. A series arrangement means that the arrangement is for example as shown in FIG. 20(a). With this arrangement, even if there is a defect in the third storage capacity counted from the switching element for example, and then this storage capacity is cut off, there are still two normally operating storage capacities left when. Consequently, brightness discrepancies to the normal pixels can be reduced and an increase in yield can be achieved. As mentioned above, providing a bypass for bypassing the storage capacity that is closest to the switching element prevents that also the other normal storage capacities are cut off simultaneously when there is a defect in that storage capacity and that storage capacity is cut off. As a result, a further increase in yield can be achieved. A parellel arrangement means that the arrangement is for example as shown in FIG. 20(b). With this arrangement, the other storage capacities can still be operated even when a storage capacity with a defect is cut off, so that a further increase in yield can be achieved. A loop arrangement means that the arrangement is for example as shown in FIG. 20(c). With this arrangement, the other storage capacities can still operate normally even when a storage capacity with a defect is cut off, so that, again, a further increase in yield can be achieved.
In order to achieve the above-stated object, a liquid crystal display device in accordance with the present invention, wherein a liquid crystal layer is formed between a pair of substrates, and wherein liquid crystal in the liquid crystal layer is driven by an electric field that is parallel to the substrate surface, wherein provided on one substrate of the pair of substrates are a plurality of gate lines, a plurality of data lines provided such that the data lines intersect with the plurality of gate lines, switching elements associated with points where the plurality of gate lines and the plurality of data lines intersect, and which are connected to the gates lines and the data lines, pixel electrodes connected to the data lines via the switching elements; and opposing electrodes forming pairs with the pixel electrodes, wherein the pixel electrodes overlap with a portion of the previous or subsequent gate line of the plurality of gate lines, and/or with a portion of the opposing electrode, at a plurality of locations via an insulating layer, and wherein at least two of the plurality of overlaps form storage capacities.
In this configuration, it is further possible to adopt a configuration wherein, even if a portion of the pixel electrode forming one storage capacity of the at least two storage capacities in the pixel electrode is cut off, a portion of the pixel electrode forming the other storage capacities is still connected to the switching element.
With this configuration, at least two of the plurality of overlaps in the pixels function as storage capacities, so that even if for example one of them does not operate normally due to an electrical short-circuit, and the storage capacity with the defect is cut off, fluctuations of the potential level of the pixel electrode can be inhibited by the other storage capacity. As a result, extreme discrepancies in brightness and flicker properties compared to the normal pixel do not occur. Thus, bad pixels can be made more inconspicuous on the display screen, and an increase in yield can be achieved.
In the above configuration, it is further possible to adopt a configuration in which the pixel electrodes include a plurality of pixel electrode portions that are provided parallel to one another and that generate the parallel electric field between the pixel electrode and the opposing electrode, and an electrode linking portion for linking the plurality of pixel electrode portions, wherein storage capacities are formed by the electrode linking portion overlapping with a portion of the previous or subsequent gate line and/or with a portion the opposing electrode.
In the above configuration, it is further possible to adopt a configuration in which the pixel electrodes include a plurality of pixel electrode portions that are provided parallel to one another, an electrode linking portion for linking the plurality of pixel electrode portions, and a storage capacity electrode for forming the storage capacities, wherein the storage capacity electrode forms a storage capacity by overlapping with a portion of the previous or subsequent gate line and/or a portion of the opposing electrode.
In the above configuration, it is further possible to adopt a configuration in which the electrode linking portion forms a storage capacity by overlapping with a portion of the previous or subsequent gate line and/or with a portion of the opposing electrode.
It is also possible that the storage capacity electrode is connected to the pixel electrode portions via a connection electrode wire. Even if a storage capacity electrode is cut off from the pixel electrode due to an electrical short-circuit between the storage capacity electrode and a portion of the previous or subsequent gate line and/or with a portion of the opposing electrode, the storage capacity electrode can be cut off easily by severing the connection electrode wire. Thus, it can be prevented that for example another pixel electrode portion is also cut off as well when the storage capacity electrode is cut off, and the maximum displayable region can be kept. As a result, bad pixels in the display screen can be made even more inconspicuous.
In addition, in this configuration, it is also possible to adopt a configuration in which the wire width of at least a portion of the connection electrode wire is smaller than the width of the pixel electrode portions. Thus, the connection electrode wire can be easily severed when the storage capacity electrode is cut off from the pixel electrode.
Moreover, in the above configuration, it is also possible to adopt a configuration in which the connection electrode wire is provided with a separation portion for separation by laser light, wherein the separation portion is further provided with a marking. Providing the connection electrode wire with a separation portion, and further providing the separation portion with a marking makes the severing of the connection electrode wire easier. As a result, a liquid crystal display device in which repair of bad pixel by laser repair is easy can be provided.
Moreover, in the above configuration, it is also possible to adopt a configuration in which the areas of the overlaps forming the at least two storage capacities are different. When a portion of a storage capacity with a defect, of two or more storage capacities, is separated, the storage capacity is cut of from the circuit configuration, so that the capacity of the storage capacity in the entire pixel is decreased. There is also the case that the liquid crystal capacity is decreased when a portion of the pixel electrode is separated. Thus, after separation of a portion of the pixel electrode, the ratio between storage capacity and liquid crystal capacity changes. However, when the areas of the overlaps constituting the storage capacities are different, as in the above-described configuration, so that the storage capacities are made different from one another, then it becomes possible to suppress fluctuations in the ratio between liquid crystal capacity and storage capacity. As a result the discrepancy to the brightness of normal pixels becomes small, and it can be prevented that the flicker properties are changed considerably, so that it is possible to provide a liquid crystal display device, in which bad pixels are not conspicuous.
Moreover, in the above configuration, it is also possible to adopt a configuration in which the switching elements are connected to the pixel electrodes via a drain electrode, wherein the drain electrode and/or the pixel electrode is provided with at least one separable compensation capacity electrode, which forms a compensation capacity by overlapping, via the insulating layer, with a portion of the corresponding gate line of the plurality of gate lines. With this configuration, even when the ratio of the sum of the liquid crystal capacity and the storage capacity to the compensation capacity changes due to cutting off a storage capacity with a defect of two or more storage capacities, the compensation capacity can be adjusted for example by separating a compensation capacity electrode. As a result, the ratio of the sum of the liquid crystal capacity and the storage capacity to the compensation capacity (also revered to in short as xe2x80x9cratio of the capacitiesxe2x80x9d below) can be brought near the value in a normal pixel, and bad pixels in the display screen can be made even more inconspicuous.
Moreover, in the above configuration, it is also possible to adopt a configuration in which, if there is a plurality of compensation capacity electrodes, the areas of the overlaps of the compensation capacity electrodes with a portion of the gate line are different. With this configuration, the compensation capacities formed between the compensation electrodes and portions of the gate lines are caused to be different from one another by making the overlap areas of the compensation capacity electrodes with portions of the gate lines different. Thus, if a storage capacity is cut off, the capacity of the storage capacities can be further fine-tuned by for example, separating a plurality of compensation capacity as necessary, so that the ratio of the capacities can be brought even closer to the value in a normal pixel.
In order to achieve the above-stated object, an array substrate in accordance with the present invention includes a plurality of gate lines; a plurality of data lines provided such that the data lines intersect with the plurality of gate lines; switching elements associated with points where the plurality of gate lines and the plurality of data lines intersect, and which are connected to the gates lines and the data lines; pixel electrodes connected to the data lines via the switching elements; and opposing electrodes forming pairs with the pixel electrodes; wherein a plurality of storage capacities for maintaining a charge of the pixel electrodes are provided in a distributed arrangement associated with points where the plurality of gate lines and the plurality of data lines intersect.
In order to achieve the above-stated object, a liquid crystal television in accordance with the present invention, wherein a liquid crystal layer is formed between a pair of substrates, and wherein liquid crystal in the liquid crystal layer is driven by an electric field that is parallel to the substrate surface, wherein provided on one substrate of the pair of substrates are a plurality of gate lines, a plurality of data lines provided such that the data lines intersect with the plurality of gate lines, switching elements associated with points where the plurality of gate lines and the plurality of data lines intersect, and which are connected to the gates lines and the data lines, pixel electrodes connected to the data lines via the switching elements, and opposing electrodes forming pairs with the pixel electrodes, wherein the pixel electrodes overlap with a portion of the previous or subsequent gate line of the plurality of gate lines, and/or with a portion of the opposing electrode, at a plurality of locations via an insulating layer, and wherein at least two of the plurality of overlaps form storage capacities.
With this configuration, even when one of two ore more storage capacities is not operating normally due to an electrical short-circuit, and the storage capacity with the defect is cut off, fluctuations in the electrical potential level of the pixel electrode are suppressed by the other storage capacities, so that no extreme discrepancy in the brightness and flicker properties as compared to normal pixels occur. Thus, even in a liquid crystal television with large pixel size, repaired pixels can be made inconspicuous on the display screen, and the repaired pixels can be kept from becoming visible. Thus, a liquid crystal television is provided that can be manufactured with increased yield.
In order to achieve the above-stated object, a pixel repair method for a liquid crystal display device in accordance with the present invention, wherein a liquid crystal in a liquid crystal layer is driven by an electric field parallel to a substrate, the liquid crystal display device including a first substrate provided with a plurality of gate lines, a plurality of data lines provided such that the data lines intersect with the plurality of gate lines, switching elements associated with points where the plurality of gate lines and the plurality of data lines intersect and which are connected to the gates lines and the data lines, pixel electrodes connected to the data lines via the switching elements, and opposing electrodes forming pairs with the pixel electrodes; a second substrate in opposition to the first substrate; and a liquid crystal layer provided between the first substrate and the second substrate; wherein the pixel electrodes overlap with a portion of the previous or subsequent gate line of the plurality of gate lines and/or with a portion of the opposing electrodes, at a plurality of locations via an insulating layer; wherein at least two of the plurality of overlaps form storage capacities; includes, when an electrical short-circuit occurs at an overlap, separating in the pixel electrode a predetermined location on the switching element side in proximity to the short-circuit, or predetermined locations in front of and behind the proximity of the short-circuit.
With this method, when an electrical short-circuit occurs between the pixel electrode and a portion of the previous or subsequent gate line of the plurality of gate lines and/or a portion of the opposing electrodes, then the pixel electrode is separated at a predetermined location on the switching element side in proximity to the short-circuit, or at predetermined locations in front of and behind the proximity of the short-circuit, so that in the region of the pixel electrode that has not been cut off from the switching element, display is possible. Moreover, even when the portion of the pixel electrode that has been cut off relates to a storage capacity, since at least two storage capacities are provided, the other storage capacities fulfill the function of holding charges necessary for display. Thus, with this method, it can be prevented that the pixel turns into a pixel that does not illuminate, even when short-circuits occur at a plurality of overlap portions. In addition, when a short-circuit occur at an overlap portion constituting the storage capacity, the other storage capacities still function and compensate for that storage capacity, so that an extreme brightness drop of repaired pixels compared to normal pixels can be averted. Thus, with this method, the repaired pixels in the display screen can be made inconspicuous, and an increase in yield can be achieved.
In this method, separation can be performed in order starting with an overlapping portion furthest from the switching element. With this method, it can be prevented that portions of the pixel element that are related to overlap portions in which there is no short-circuit are needlessly cut off.
Furthermore, in this method, it is possible to inspect display of the pixel each time separation is performed in order starting with the overlapping portion furthest from the switching element.
Furthermore, in this method, if the pixel electrode overlaps between the previous or subsequent gate line and a portion of the opposing electrode, it is possible to perform separation after it has been determined whether an electrical short-circuit is occurring between the pixel electrode and the previous or subsequent gate line or between the pixel electrode and the opposing electrode. With this method, since storage capacities are formed between the pixel electrode and a portion of the previous or subsequent gate line and between the pixel electrode and a portion of the opposing electrode, as long as it has been found in which of the two the short-circuit occurs, the steps of separating the pixel electrode can be cut in half, which makes the task more efficient.
Furthermore, in this method, the pixel electrodes is provided with a plurality of pixel electrode portions that are disposed parallel to one another and generate a parallel electrical field between the pixel electrodes and the opposing electrodes, and an electrode linking portion for linking the plurality of pixel electrode portions; and if the storage capacities are formed by the electrode linking portions overlapping with a portion of the previous or subsequent gate line and/or a portion of the opposing electrode, and an electrical short-circuit occurs at the overlaps, the electrode linking portion with the short-circuit can be cut off from the pixel electrode by separating one or more predetermined locations in the pixel electrode.
Furthermore, in this method, the pixel electrodes is provided with a plurality of pixel electrode portions disposed parallel to one another, an electrode linking portion for linking the plurality of pixel electrode portions, and storage capacity electrodes for forming the storage capacities; and if the storage capacity electrodes form storage capacities by overlapping with a portion of the previous or subsequent gate line and/or a portion of the opposing electrode, and an electrical short-circuit occurs at the overlaps, the storage capacity electrode with the short-circuit can be cut off from the pixel electrode by separating one or more predetermined location in the pixel electrode.
Furthermore, in this method, if the storage capacity electrodes are connected to the pixel electrode portions via a connection electrode wire, the storage capacity electrode with the short-circuit can be cut off from the pixel electrode by separating a predetermined location in the connection electrode wire.
Moreover, in this method, the separation can be performed by irradiating laser light.
Moreover, in this method, before the separation, defect scanning can be performed in order to detect contaminants adhering to the first substrate, and furthermore, when a contaminant is detected, that contaminant can be removed by irradiating a laser on the contaminant. With this method, it can be prevented that repair by separation is extended to defects for which there is no need for separation, and thus, an increase in yield can be achieved.
In order to achieve the above-stated object, a drive method for a liquid crystal display device in accordance with the present invention, the liquid crystal display device including a first substrate provided with a plurality of gate lines, a plurality of data lines provided such that the data lines intersect with the plurality of gate lines, switching elements associated with points where the plurality of gate lines and the plurality of data lines intersect and which are connected to the gates lines and the data lines, pixel electrodes connected to the data lines via the switching elements, and opposing electrodes forming pairs with the pixel electrodes; a second substrate in opposition to the first substrate; and a liquid crystal layer provided between the first substrate and the second substrate; wherein the pixel electrodes overlap with a portion of the previous or subsequent gate line of the plurality of gate lines and/or with a portion of the opposing electrodes, at a plurality of locations via an insulating layer; wherein at least two of the plurality of overlaps form storage capacities; the method including if there is a repaired pixel that has been repaired by separating, for a bad pixel with an electrical short-circuit at an overlap, in the pixel electrode of that bad pixel a predetermined location on the switching element side in proximity to the short-circuit, or predetermined locations in front of and behind the proximity of the short-circuit, compensating a data signal applied to the repaired pixel and driving the pixel, based on information on the pixel location of the repaired pixel and the repaired location in the repaired pixel.
With this method, the storage capacity in a repaired pixel can be calculated from the repair position in the repaired pixel. Considering the drop in the brightness of the repaired pixel in comparison to normal pixels depending on this capacity, a compensated data signal is applied to the repaired pixel. As a result, it is possible to drive the pixels such that the brightness of the repaired pixel is close to the brightness of normal pixels, and thus, repaired pixels in the display screen can be made even more inconspicuous. It should be noted that, xe2x80x9ccompensated data signalxe2x80x9d means a data signal with a voltage that is higher than the voltage of a data signal applied to a normal pixel. It is also possible to compensate data signals based on information on the pixel position and the repair position in repaired pixels.